In recent years, the vehicle cruise control apparatus for controlling the host vehicle to travel to follow a preceding vehicle traveling ahead has been developed in order to reduce the manipulation load on the driver driving the vehicle. This cruise control apparatus is arranged to control the acceleration of the host vehicle, for example, so that the inter-vehicular distance between the preceding vehicle detected by a sensor such as a camera or a radar, and the host vehicle becomes a target inter-vehicular distance.
An example of such cruise control apparatus is the automatic follow-up control apparatus disclosed in Japanese Patent Application Laid-Open No. 2003-200751. This automatic follow-up control apparatus is arranged to detect an angle of the preceding vehicle relative to the position of the host vehicle and an inclination of the preceding vehicle made by a direction of the host vehicle and a direction of the preceding vehicle on the occasion of performing the follow-up control, and to estimate a radius of a curve that the host vehicle is about to enter, from the detected angle and inclination. An acceleration of the host vehicle is determined according to the radius of the curve.